Preparation of Mercurial Ointment. 1@7 
position of this acid ; a statement perfectly opposite to fact, 
at least as far as concerns hydrochloric acid. I prepared 
four ounces of hydrocyanic acid perfectly pure by distilla- 
tion off chalk; to two ounces I added five drops of hydro- 
chloric acid; the other two ounces in another phial were left 
perfectly pure, both inverted and placed in a glass case, so as 
to have diffused light during the day. After three weeks the 
pure acid had become quite brown, and a considerable quan- 
tity of solid deposit had formed ; the other remained quite 
limpid and colourless, and on actual trial was found to con- 
tain nineteen-twentieths of the acid which it had at first. Mr. 
Barry also informed me that his fourteen years' experience 
led to the same result; and that, being aware of this, he adds 
purposely a little hydrochloric acid to all his medicinal acid. 
Perhaps some may object to the price of the preparation : a 
case containing the two bottles with 200 grains of the cyanide 
would leave one-half profit if sold for 5s.; this brings an ounce 
of acid to Is., and where so small a quantity is used, surely 
this cannot be a very weighty objection, if a uniform article 
can be secured. — London and Edinburg Philosophical Mag. 
ART. XXXVIII.— ON THE PREPARATION OF MERCURIAL 
OINTMENT. 
By M. COLDEFY DORLY. 
The possibility of promptly killing mercury by prepared 
lard, having been doubted, I have the honour of sending to 
the Society of Pharmacy a specimen of axunge, by which 
twenty-four to thirty-two times its weight of mercury can be 
extinguished in a few minutes. 
About five years since, I laid before the Society a series of 
manipulations, among which was the following, and which I 
preferred. 
After having melted the axunge, it is to be poured in a 
